Objective: To investigate whether TRIM59 regulates invasion and metastasis of nasopharyngeal carcinoma cells by targeting PPM1B.
Method: We analyzed the expression of TRIM59 in nasopharyngeal carcinoma tissues based on data from TCGA database and detected the expressions of TRIM59 and PPM1B in nasopharyngeal carcinoma and adjacent tissues using Western blotting. We also detected the expressions of TRIM59 and PPM1B at both the mRNA and protein levels in nasopharyngeal carcinoma cell lines using RT-PCR and Western blotting. Stable cell lines with TRIM59 overexpression or knockdown were established in HNE1 cells, in which the targeting relationship between TRIM59 and PPM1B was analyzed using Western blotting and a luciferase reporter gene assay. Transwell chamber assay was used to assess changes in the invasion and migration abilities of HNE1 cells with TRIM59 overexpression or knockdown.
Results: Analysis based on TCGA database showed that TRIM59 expression was significantly higher in nasopharyngeal carcinoma tissues than in adjacent tissues (P=0.006); the expression of TRIM59 increased (P=0.01) and PPM1B expression decreased significantly (P=0.03) in nasopharyngeal carcinoma tissues. Compared with HNEpC cells, HNE1 cells expressed a significantly higher level of TRIM59 (P=0.04) but a lower level of PPM1B (P=0.01). Luciferase reporter gene assay indicated that PPM1B was a downstream target gene of TRIM59 and its expression was negatively correlated with TRIM59 expression (P=0.01). In HNE1 cells, TRIM59 overexpression significantly promoted cell invasion (P=0.01) and migration (P=0.02) while TRIM59 knockdown obviously suppressed cell invasion (P=0.01) and migration (P=0.01). TRIM59 knockdown with simultaneous PPM1B overexpression more strongly inhibited invasion (P=0.02) and migration (P=0.01) of HNE1 cells as compared with TRIM59 knockdown alone.
Conclusion: TRIM59 regulates invasion and migration of nasopharyngeal carcinoma cells through targeted modulation of PPM1B.
目的: 探讨TRIM59能否通过靶向PPM1B影响鼻咽癌侵袭和迁移。
方法: TCGA数据库分析TRIM59在鼻咽癌中的表达；Western blot实验检测TRIM59和PPM1B在鼻咽癌和癌旁组织中的表达情况；RT-PCR和Western blot实验分别检测鼻咽癌细胞系中TRIM59和PPM1B mRNA和蛋白的相对表达量；建立HNE1细胞TRIM59过表达及抑制表达的稳定细胞系，实验设未转染组（Control）、模拟物阴性对照组（mimic NC）、TRIM59模拟物组（mimic-TRIM59）、抑制剂阴性对照组（inhibitor NC）及TRIM59抑制剂组（si-TRIM59）。Western blot和荧光素酶报告基因实验检测TRIM59和PPM1B靶向关系；Transwell小室检测HNE1细胞侵袭和迁移能力的变化。
结果: TCGA数据库结果表明，TRIM59在鼻咽癌组织中的表达明显高于癌旁组织（P=0.006）；TRIM59在鼻咽癌组织中表达增加（P=0.01）且PPM1B表达下降（P=0.03）；与HNEpC细胞相比，TRIM59在HNE1细胞中相对表达量显著增加（P=0.04），PPM1B在HNE1细胞中相对表达量显著下降（P=0.02）；PPM1B为TRIM59下游靶基因且与TRIM59表达呈负相关（P=0.01）；Transwell结果显示，上调TRIM59表达，HNE1细胞侵袭和迁移能力增强（P=0.01，P=0.02），下调TRIM59表达，HNE1细胞侵袭和迁移能力受到显著抑制（P=0.01）；同时下调TRIM59且上调PPM1B表达后，HNE1细胞侵袭和迁移能力均较单独下调TRIM59表达显著被抑制（P=0.02，P=0.01）。
结论: TRIM59通过靶向调控PPM1B影响鼻咽癌细胞侵袭和转移。
Keywords: PPM1B; TRIM59; invasion; migration; nasopharyngeal carcinoma.